Also called tricyclic antidepressant.Pharmacology. any of a group of pharmacologically active substances, as imipramine, that share a common three-ring structure, used to treat depression and cocaine abuse.

tricyclic

[trī-sī′klĭk, -sĭk′lĭk]

Relating to a chemical compound having three closed rings. Anthracene is a tricyclic hydrocarbon.

Relating to a class of drugs used to treat depression and having a tricyclic chemical structure consisting of two benzene rings fused to opposite sides of a seven-member ring. The seven-member ring consists of six carbon atoms and one nitrogen atom. Tricyclic antidepressants enhance the activity of monoamine neurotransmitters in the brain by inhibiting their reuptake by the cells that secrete them.

Composed of or arranged in three distinct whorls, as the petals of a flower.